Reconfigurable saws of various kinds are well-known in the art, as evidenced by the following United States patents:
No. 1,028,230No. 2,782,821No. 1,245,345No. 4,680,863No. 2,173,365No. 5,873,170No. 2,514,880The incorporation of a pivotable arm into a hacksaw frame is disclosed in U.S. Pat. Nos. 2,309,816 and 5,471,752, and the following United States patents provide a variety of blade-tensioning arrangements:
Des. 428,321No. 1,565,861No. 766,077No. 3,636,997No. 1,080,365No. 4,349,059No. 1,187,460No. 6,070,330No. 1,517,827No. 6,079,109Additional forms of saws are disclosed in the following United States patents:
Des. 318,006No. 2,580,896No. 1,206,638No. 2,662,567No. 1,394,174No. 3,822,731No. 1,522,598No. 4,835,869No. 1,695,231Among the foregoing, particular note may be made of Duffy U.S. Pat. No. 4,680,863. Duffy describes a saw in which the blade can be disposed either parallel to the back member or in a number of angular relationships thereto, such variation being achieved, in part, by rotating one of three fingers into operative position.
The saw provided by Duffy would however appear to suffer from several significant drawbacks. First of all, because a plurality of laterally stacked fingers are employed the limited space available requires each finger to be relatively thin and, therefore, to be relatively weak. The thinness of the fingers also precludes the provision of blade-mounting elements on opposite sides thereof, such as to enable orientation of the blade both parallel to a medial plane of the frame and also at an angle thereto, as is conventional (typically at an angle of 45°) and desirable. Moreover, because the fingers are spaced in different lateral planes the mounted blade must (at least when either of two of the three fingers are used) extend at an angle to the medial plane; albeit relatively small, such angular displacement would preclude accuracy of cutting (unless the saw itself were held at an artificial angle to the workpiece). Finally, because forward blade-engagement elements are provided only on the fingers of the Duffy saw, the blade must be displaced from the back member in all configurations, and minimal spacing capability cannot therefore be achieved.